Dear Rachel,
This is just a few ideas to start with which should work across all age groups with minor variations. You could start with a discussion and a chart to list student ideas - a bit like a mind map. List student knowledge of Antarctica, and also make a list on another chart of what they would like to know (find out). Also, devise a set of "discovery" questions with the kids which you guide so that you achieve learning outcomes and at the same time kids feel that they have made them up themselves (Follow Bloom's Taxonomy).
Also list possible places you could go to for information, including the net. Before beginning, it's a good idea to designate an "Antarctica" display section in your class (I used the corridor outside our room). Give it a theme name. Let the kids come up with that. You'll be pleasantly surprised. Display all charts and track what you've done with the ideas you've come up with.
You could use an exercise book for draft work. Kids like to work on projects in groups so with each new task they could write their reports in the exercise book and then write out final reports for display on cardboard or A4. PPT presentations are also good fun (at the end when the kids have sufficient background knowledge). We turned the corridor into an icy cave and stuck icicles and stuck garbage bags to the ceiling to make it look dark. It was fun but for a short person, almost impossible!!
I hope that was helpful and I'm not sure what background you have so if I've told things you already know just let me know
Good luck.
psr